1. Field
The present disclosure relates generally to manufacturing and servicing vehicles, especially aircraft. More particularly, the present disclosure relates to a coating and related method for detecting structural inconsistencies in composite aircraft parts.
2. Background
Parts fabricated from composite materials are sometimes chosen for use in the aerospace and aircraft industry because of their superior stiffness, strength, and weight in comparison to metal parts. In metal aircraft structures, a low-energy or low-velocity impact usually forms a dent on the part surface that may be easily detected during a visual inspection. In the case of composite parts however, impact events, such as ground vehicle collisions or strikes by runway debris on takeoff or landing, may not always leave an easily identifiable mark on the surface of the part. Such impact events, and the damage they cause are sometimes referred to as Barely Visible Impact Damage (BVID). Barely Visible Impact Damage resulting from low-velocity impact events may cause sub-surface damage and delamination that extend beyond the impacted surface area.
Due to the opacity and inhomogeneity of composite parts, detection of subsurface damage can be challenging. Currently, ultrasonic C-scanning is often used to detect interior flaws and damage in composite parts. However, C-scans accurate enough to detect Barely Visible Impact Damage are time consuming and may require the aircraft to be taken out of service for a thorough inspection, resulting in undesirable aircraft downtime.
Accordingly, there is a need for aircraft structures having characteristics that facilitate easy detection of Barely Visible Impact Damage during routine in-service inspections. There is also a need for Barely Visible Impact Damage detection that may reduce the need for skilled inspection technicians, and the time required to perform the inspections.